RIO DE JANEIRO: Voters across Brazil were casting ballots on Sunday in the most unpredictable presidential election in decades and the first since the end of an economic boom underpinning the leftist Workers’ Party’s 12-year rule.

As President Dilma Rousseff seeks a second term, voters are weighing whether the socioeconomic gains of the last decade are enough to reject the candidacies of a popular environmentalist and a pro-business social democrat, who both promise to jump-start the economy after four years of lackluster growth.

Polls show Rousseff as the front runner in a race that is likely to go to a runoff on Oct 26, following one of the most competitive campaigns since Brazil returned to democracy in 1985. The death of one candidate, the unexpected surge of another, and fierce marketing by Rousseff to claw back into the lead have contributed to a nail-biter election as uncertain as the course of the country itself.

“It really is too close to call,” said Rafael Cortez, a political analyst with Tendencias, a consultancy in Sao Paulo. “Volatility and frustration favour opposition candidates, but you don’t really have a crisis to topple the government, either.”

Rousseff’s main rivals are Marina Silva, a hero of the global conservation movement and ruling party defector now with the Brazilian Socialist Party, and Aecio Neves, a senator and former state governor from the centrist party that laid the groundwork for Brazil’s economic boom last decade.

At mid-day, voting was proceeding without major problems, from densely populated southern cities to remote Amazon villages.

Rousseff, wearing the Workers’ Party’s signature red, voted shortly after polls opened in the southern city of Porto Alegre, where she lived and rose in the state bureaucracy in the 1990s.

Published in Dawn, October 6th, 2014